Implement boundary asymptotics

[pbeckman]

I've translated the MATLAB routine feval_asy2 in chebfun/jacpts.m which implements the boundary asymptotics from Hale and Townsend 2012. These asymptotics are necessary to get high accuracy Gauss-Jacobi weights, particularly for large $N$ and $\alpha, \beta < -0.5$.

I've included tests which verify that issues #58 and #130 are both resolved by these changes.

This implementation relies on storing $10 \times 10$ Chebyshev differentiation and integration matrices to numerically evaluate the higher order coefficients in the relevant asymptotics. Personally I think this is a mild price to pay, and avoids reliance on other packages. However, @dlfivefifty suggested that creating a core ChebyshevTransforms.jl package to be used also by other interfaces may be a more elegant solution.

[dlfivefifty]

I think this is a good solution for now.

[hyrodium]

I have not looked into math details yet. I added some minor comments.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (c3a7394) 96.62% compared to head (5a86bc1) 96.89%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #131      +/-   ##
==========================================
+ Coverage   96.62%   96.89%   +0.26%     
==========================================
  Files           9        9              
  Lines        1244     1384     +140     
==========================================
+ Hits         1202     1341     +139     
- Misses         42       43       +1     

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[dlfivefifty]

This is certainly MATLAB-style code, but so is most of this package.... I think trying to de-matlab the code at this point is a fools-errand.

If the tests pass we should just merge and someone can improve the style/using SMatrix/etc. in a separate PR.

[pbeckman]

Sounds good. I made some of the small changes that @hyrodium suggested, and added a test to cover a few previously untested lines of the bary interpolation function. So hopefully all the Codecov tests will pass now.

[hyrodium]

Could you please add more tests for the coverage?
https://github.com/JuliaApproximation/FastGaussQuadrature.jl/pull/131/checks?check_run_id=19351711888

[pbeckman]

I've satisfied all the code coverage checks. Let me know if there's anything else I can do to get things finalized.

[dlfivefifty]

I'll merge if no one objects in the next day

[MikaelSlevinsky]

This is a great addition! It should be merged ASAP.

[hyrodium]

LGTM! Could you bump the version to v1.0.1?